Negative calorie foods refer to those items that consume more energy during its digestion, in comparison to the amount of energy it gives to the body. In another way, we can say that the calorie cost of digesting the food would be greater than its energy content. These foods are typically high in fiber and have a low glycaemic index. Calories are an important component of food and everything we eat has calories. Calories are of 2 types. One is empty calories that don’t have much nutritive value but just have calories; they promote weight gain.
Foods with high fibre and water content usually have fewer calories, and we need more energy to digest them. These are called negative calorie foods. These foods help to lose weight as they are not only low in calories, but also help to burn more calories than others. Most negative calorie foods are plant-based.
Make note of these 10 negative-calorie foods:
Celery: Celery contains 16 kcal/100g. It is rich in fibre, vitamin A, C, and folate. It is one of the most popular food items, as most of its calorie value is stored in cellulose. Our body receives very few calories from celery, as it is full of undigested fiber.
Berries: Colourful berries such as blueberries, strawberries, and raspberries typically contain just 32 kcal for a half cup quantity. They are often called negative-calorie foods, because of their low glycaemic index and its protein content. It also contains antioxidants, which protect us from various cancers.
Tomatoes: Tomatoes have 19kcal/100g. Apart from their water content, they are an excellent source of fiber, potassium, and vitamin C. Tomatoes also contain lycopene, an antioxidant known to protect us from skin cancer.
Carrots: Carrots contain 41 kcal/100g. Its vitamin A content is good for the eyes. Moreover, their fibre content keeps the stomach full for longer, which helps in weight loss.
Cucumber: Cucumber contains 15 kcal/100g. This vegetable has high water content, which is great to satisfy thirst along with providing all the necessary vitamins and minerals. The water content present in cucumber is great for hydration. Along with quenching thirst, this fruit provides dietary fibre, and helps to tackle irritable bowel syndrome and diabetes.
Watermelon: Watermelon has 30 kcal/100g. Watermelon rind helps in strengthening the heart, provides hydration, and regulates blood pressure. Additionally, watermelon seeds also have many health benefits starting from the prevention of anemia to immune-boosting properties. The water content present in watermelon and vitamins A, B6, C along with lycopene act as an immune-boosting food.
Apples: Apples provide 52 kcal/100g. They contain a good amount of antioxidants, vitamin C, and fibre. In fact, apple’s high fibre content helps in weight loss, and at the same time, boosts cognitive performance. Quercetin, an antioxidant present in apples, is also associated with a lower risk of type 2 diabetes.
Broccoli: Broccoli contains 34 kcal/100g and is a powerhouse of vitamin A that improves vision. Calcium, phosphorus, and vitamin K content is essential for healthy bone development, while iron and folic acid help to prevent anemia. Kaempferol, a flavonoid present in broccoli, has anti-inflammatory properties. Broccoli is also rich in alpha-linolenic acid(ALA), which is crucial for brain growth and development.
Zucchini: Zucchini contains about 17 kcal/100g and is packed with many important vitamins, minerals, and antioxidants. It has high fibre content and a low-calorie count. Fibre plays an important role in digestion. Zeaxanthin, present in zucchini, plays an important role in preventing oxidative stress and improves eye health.
Lettuce: Lettuce provides about 15 kcal/100g. Its vitamin C, K, and A content as well as calcium help in boosting immunity. The fibre content of lettuce helps in weight loss, and is also associated with a healthy heart and maintaining eye health.
There is no evidence that eating negative calorie foods leads to side effects. However, directly eating low amounts of calories is not advised, if you are not under the supervision of a dietitian. The calorie requirement to reduce weight is individualized. The requirement varies depending on the person’s height, weight, BMI, BMR, and physical activity.
These foods can be added to our daily diet as snacks or cooking ingredients. Cucumber, tomatoes, carrots and lettuce can be used in various salads. Berries, apples, or watermelon can be consumed as a mid-morning or evening snack. Broccoli, zucchini or lettuce can be used in various preparations during cooking.